In my car, here is what I removed:
1. CD player/tape deck
2. amplifier from up front (it was located below the cd player)
3. Rear deck w/ two speakers and tweeters
4. two amplifiers in trunk, which were right behind the rear speaker deck
5. the two door speakers
6. The two tweeters in the tweeter pod above both doors
I didn't remove any factory wiring yet.